Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * kallsyms.c: in-kernel printing of symbolic oopses and stack traces. | |
3 | * | |
4 | * Rewritten and vastly simplified by Rusty Russell for in-kernel | |
5 | * module loader: | |
6 | * Copyright 2002 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation | |
7 | * | |
8 | * ChangeLog: | |
9 | * | |
10 | * (25/Aug/2004) Paulo Marques <pmarques@grupopie.com> | |
11 | * Changed the compression method from stem compression to "table lookup" | |
12 | * compression (see scripts/kallsyms.c for a more complete description) | |
13 | */ | |
14 | #include <linux/kallsyms.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/seq_file.h> | |
18 | #include <linux/fs.h> | |
67fc4e0c | 19 | #include <linux/kdb.h> |
1da177e4 LT |
20 | #include <linux/err.h> |
21 | #include <linux/proc_fs.h> | |
4e57b681 | 22 | #include <linux/sched.h> /* for cond_resched */ |
1da177e4 | 23 | #include <linux/mm.h> |
07354a00 | 24 | #include <linux/ctype.h> |
5a0e3ad6 | 25 | #include <linux/slab.h> |
74451e66 | 26 | #include <linux/filter.h> |
aba4b5c2 | 27 | #include <linux/ftrace.h> |
52f5684c | 28 | #include <linux/compiler.h> |
1da177e4 LT |
29 | |
30 | #include <asm/sections.h> | |
31 | ||
ad6ccfad MK |
32 | /* |
33 | * These will be re-linked against their real values | |
34 | * during the second link stage. | |
35 | */ | |
52f5684c | 36 | extern const unsigned long kallsyms_addresses[] __weak; |
2213e9a6 | 37 | extern const int kallsyms_offsets[] __weak; |
52f5684c | 38 | extern const u8 kallsyms_names[] __weak; |
1da177e4 | 39 | |
ad6ccfad MK |
40 | /* |
41 | * Tell the compiler that the count isn't in the small data section if the arch | |
42 | * has one (eg: FRV). | |
9e6c1e63 DH |
43 | */ |
44 | extern const unsigned long kallsyms_num_syms | |
2ea03891 | 45 | __attribute__((weak, section(".rodata"))); |
9e6c1e63 | 46 | |
2213e9a6 AB |
47 | extern const unsigned long kallsyms_relative_base |
48 | __attribute__((weak, section(".rodata"))); | |
49 | ||
52f5684c GID |
50 | extern const u8 kallsyms_token_table[] __weak; |
51 | extern const u16 kallsyms_token_index[] __weak; | |
1da177e4 | 52 | |
52f5684c | 53 | extern const unsigned long kallsyms_markers[] __weak; |
1da177e4 LT |
54 | |
55 | static inline int is_kernel_inittext(unsigned long addr) | |
56 | { | |
57 | if (addr >= (unsigned long)_sinittext | |
58 | && addr <= (unsigned long)_einittext) | |
59 | return 1; | |
60 | return 0; | |
61 | } | |
62 | ||
63 | static inline int is_kernel_text(unsigned long addr) | |
64 | { | |
128e8db3 MF |
65 | if ((addr >= (unsigned long)_stext && addr <= (unsigned long)_etext) || |
66 | arch_is_kernel_text(addr)) | |
1da177e4 | 67 | return 1; |
cae5d390 | 68 | return in_gate_area_no_mm(addr); |
1da177e4 LT |
69 | } |
70 | ||
71 | static inline int is_kernel(unsigned long addr) | |
72 | { | |
73 | if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) | |
74 | return 1; | |
cae5d390 | 75 | return in_gate_area_no_mm(addr); |
1da177e4 LT |
76 | } |
77 | ||
ffc50891 FBH |
78 | static int is_ksym_addr(unsigned long addr) |
79 | { | |
63b23e2c | 80 | if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) |
ffc50891 FBH |
81 | return is_kernel(addr); |
82 | ||
a3b81113 | 83 | return is_kernel_text(addr) || is_kernel_inittext(addr); |
ffc50891 FBH |
84 | } |
85 | ||
ad6ccfad MK |
86 | /* |
87 | * Expand a compressed symbol data into the resulting uncompressed string, | |
e3f26752 | 88 | * if uncompressed string is too long (>= maxlen), it will be truncated, |
ad6ccfad MK |
89 | * given the offset to where the symbol is in the compressed stream. |
90 | */ | |
e3f26752 CG |
91 | static unsigned int kallsyms_expand_symbol(unsigned int off, |
92 | char *result, size_t maxlen) | |
1da177e4 LT |
93 | { |
94 | int len, skipped_first = 0; | |
aad09470 | 95 | const u8 *tptr, *data; |
1da177e4 | 96 | |
ad6ccfad | 97 | /* Get the compressed symbol length from the first symbol byte. */ |
1da177e4 LT |
98 | data = &kallsyms_names[off]; |
99 | len = *data; | |
100 | data++; | |
101 | ||
ad6ccfad MK |
102 | /* |
103 | * Update the offset to return the offset for the next symbol on | |
104 | * the compressed stream. | |
105 | */ | |
1da177e4 LT |
106 | off += len + 1; |
107 | ||
ad6ccfad MK |
108 | /* |
109 | * For every byte on the compressed symbol data, copy the table | |
110 | * entry for that byte. | |
111 | */ | |
112 | while (len) { | |
113 | tptr = &kallsyms_token_table[kallsyms_token_index[*data]]; | |
1da177e4 LT |
114 | data++; |
115 | len--; | |
116 | ||
117 | while (*tptr) { | |
ad6ccfad | 118 | if (skipped_first) { |
e3f26752 CG |
119 | if (maxlen <= 1) |
120 | goto tail; | |
1da177e4 LT |
121 | *result = *tptr; |
122 | result++; | |
e3f26752 | 123 | maxlen--; |
1da177e4 LT |
124 | } else |
125 | skipped_first = 1; | |
126 | tptr++; | |
127 | } | |
128 | } | |
129 | ||
e3f26752 CG |
130 | tail: |
131 | if (maxlen) | |
132 | *result = '\0'; | |
1da177e4 | 133 | |
ad6ccfad | 134 | /* Return to offset to the next symbol. */ |
1da177e4 LT |
135 | return off; |
136 | } | |
137 | ||
ad6ccfad MK |
138 | /* |
139 | * Get symbol type information. This is encoded as a single char at the | |
140 | * beginning of the symbol name. | |
141 | */ | |
1da177e4 LT |
142 | static char kallsyms_get_symbol_type(unsigned int off) |
143 | { | |
ad6ccfad MK |
144 | /* |
145 | * Get just the first code, look it up in the token table, | |
146 | * and return the first char from this token. | |
147 | */ | |
148 | return kallsyms_token_table[kallsyms_token_index[kallsyms_names[off + 1]]]; | |
1da177e4 LT |
149 | } |
150 | ||
151 | ||
ad6ccfad MK |
152 | /* |
153 | * Find the offset on the compressed stream given and index in the | |
154 | * kallsyms array. | |
155 | */ | |
1da177e4 LT |
156 | static unsigned int get_symbol_offset(unsigned long pos) |
157 | { | |
aad09470 | 158 | const u8 *name; |
1da177e4 LT |
159 | int i; |
160 | ||
ad6ccfad MK |
161 | /* |
162 | * Use the closest marker we have. We have markers every 256 positions, | |
163 | * so that should be close enough. | |
164 | */ | |
165 | name = &kallsyms_names[kallsyms_markers[pos >> 8]]; | |
1da177e4 | 166 | |
ad6ccfad MK |
167 | /* |
168 | * Sequentially scan all the symbols up to the point we're searching | |
169 | * for. Every symbol is stored in a [<len>][<len> bytes of data] format, | |
170 | * so we just need to add the len to the current pointer for every | |
171 | * symbol we wish to skip. | |
172 | */ | |
173 | for (i = 0; i < (pos & 0xFF); i++) | |
1da177e4 LT |
174 | name = name + (*name) + 1; |
175 | ||
176 | return name - kallsyms_names; | |
177 | } | |
178 | ||
2213e9a6 AB |
179 | static unsigned long kallsyms_sym_address(int idx) |
180 | { | |
181 | if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) | |
182 | return kallsyms_addresses[idx]; | |
183 | ||
184 | /* values are unsigned offsets if --absolute-percpu is not in effect */ | |
185 | if (!IS_ENABLED(CONFIG_KALLSYMS_ABSOLUTE_PERCPU)) | |
186 | return kallsyms_relative_base + (u32)kallsyms_offsets[idx]; | |
187 | ||
188 | /* ...otherwise, positive offsets are absolute values */ | |
189 | if (kallsyms_offsets[idx] >= 0) | |
190 | return kallsyms_offsets[idx]; | |
191 | ||
192 | /* ...and negative offsets are relative to kallsyms_relative_base - 1 */ | |
193 | return kallsyms_relative_base - 1 - kallsyms_offsets[idx]; | |
194 | } | |
195 | ||
1da177e4 LT |
196 | /* Lookup the address for this symbol. Returns 0 if not found. */ |
197 | unsigned long kallsyms_lookup_name(const char *name) | |
198 | { | |
9281acea | 199 | char namebuf[KSYM_NAME_LEN]; |
1da177e4 LT |
200 | unsigned long i; |
201 | unsigned int off; | |
202 | ||
203 | for (i = 0, off = 0; i < kallsyms_num_syms; i++) { | |
e3f26752 | 204 | off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); |
1da177e4 LT |
205 | |
206 | if (strcmp(namebuf, name) == 0) | |
2213e9a6 | 207 | return kallsyms_sym_address(i); |
1da177e4 LT |
208 | } |
209 | return module_kallsyms_lookup_name(name); | |
210 | } | |
f60d24d2 | 211 | EXPORT_SYMBOL_GPL(kallsyms_lookup_name); |
1da177e4 | 212 | |
75a66614 AK |
213 | int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, |
214 | unsigned long), | |
215 | void *data) | |
216 | { | |
217 | char namebuf[KSYM_NAME_LEN]; | |
218 | unsigned long i; | |
219 | unsigned int off; | |
220 | int ret; | |
221 | ||
222 | for (i = 0, off = 0; i < kallsyms_num_syms; i++) { | |
e3f26752 | 223 | off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); |
2213e9a6 | 224 | ret = fn(data, namebuf, NULL, kallsyms_sym_address(i)); |
75a66614 AK |
225 | if (ret != 0) |
226 | return ret; | |
227 | } | |
228 | return module_kallsyms_on_each_symbol(fn, data); | |
229 | } | |
230 | EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol); | |
231 | ||
ffc50891 FBH |
232 | static unsigned long get_symbol_pos(unsigned long addr, |
233 | unsigned long *symbolsize, | |
234 | unsigned long *offset) | |
235 | { | |
236 | unsigned long symbol_start = 0, symbol_end = 0; | |
237 | unsigned long i, low, high, mid; | |
238 | ||
2ea03891 | 239 | /* This kernel should never had been booted. */ |
2213e9a6 AB |
240 | if (!IS_ENABLED(CONFIG_KALLSYMS_BASE_RELATIVE)) |
241 | BUG_ON(!kallsyms_addresses); | |
242 | else | |
243 | BUG_ON(!kallsyms_offsets); | |
2ea03891 | 244 | |
ad6ccfad | 245 | /* Do a binary search on the sorted kallsyms_addresses array. */ |
ffc50891 FBH |
246 | low = 0; |
247 | high = kallsyms_num_syms; | |
248 | ||
249 | while (high - low > 1) { | |
2fc9c4e1 | 250 | mid = low + (high - low) / 2; |
2213e9a6 | 251 | if (kallsyms_sym_address(mid) <= addr) |
ffc50891 FBH |
252 | low = mid; |
253 | else | |
254 | high = mid; | |
255 | } | |
256 | ||
257 | /* | |
ad6ccfad MK |
258 | * Search for the first aliased symbol. Aliased |
259 | * symbols are symbols with the same address. | |
ffc50891 | 260 | */ |
2213e9a6 | 261 | while (low && kallsyms_sym_address(low-1) == kallsyms_sym_address(low)) |
ffc50891 FBH |
262 | --low; |
263 | ||
2213e9a6 | 264 | symbol_start = kallsyms_sym_address(low); |
ffc50891 | 265 | |
ad6ccfad | 266 | /* Search for next non-aliased symbol. */ |
ffc50891 | 267 | for (i = low + 1; i < kallsyms_num_syms; i++) { |
2213e9a6 AB |
268 | if (kallsyms_sym_address(i) > symbol_start) { |
269 | symbol_end = kallsyms_sym_address(i); | |
ffc50891 FBH |
270 | break; |
271 | } | |
272 | } | |
273 | ||
ad6ccfad | 274 | /* If we found no next symbol, we use the end of the section. */ |
ffc50891 FBH |
275 | if (!symbol_end) { |
276 | if (is_kernel_inittext(addr)) | |
277 | symbol_end = (unsigned long)_einittext; | |
63b23e2c | 278 | else if (IS_ENABLED(CONFIG_KALLSYMS_ALL)) |
ffc50891 FBH |
279 | symbol_end = (unsigned long)_end; |
280 | else | |
281 | symbol_end = (unsigned long)_etext; | |
282 | } | |
283 | ||
ffb45122 AD |
284 | if (symbolsize) |
285 | *symbolsize = symbol_end - symbol_start; | |
286 | if (offset) | |
287 | *offset = addr - symbol_start; | |
ffc50891 FBH |
288 | |
289 | return low; | |
290 | } | |
291 | ||
292 | /* | |
293 | * Lookup an address but don't bother to find any names. | |
294 | */ | |
295 | int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, | |
296 | unsigned long *offset) | |
297 | { | |
6dd06c9f | 298 | char namebuf[KSYM_NAME_LEN]; |
74451e66 | 299 | |
ffc50891 FBH |
300 | if (is_ksym_addr(addr)) |
301 | return !!get_symbol_pos(addr, symbolsize, offset); | |
74451e66 DB |
302 | return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf) || |
303 | !!__bpf_address_lookup(addr, symbolsize, offset, namebuf); | |
ffc50891 FBH |
304 | } |
305 | ||
1da177e4 LT |
306 | /* |
307 | * Lookup an address | |
ad6ccfad MK |
308 | * - modname is set to NULL if it's in the kernel. |
309 | * - We guarantee that the returned name is valid until we reschedule even if. | |
310 | * It resides in a module. | |
311 | * - We also guarantee that modname will be valid until rescheduled. | |
1da177e4 LT |
312 | */ |
313 | const char *kallsyms_lookup(unsigned long addr, | |
314 | unsigned long *symbolsize, | |
315 | unsigned long *offset, | |
316 | char **modname, char *namebuf) | |
317 | { | |
74451e66 DB |
318 | const char *ret; |
319 | ||
9281acea | 320 | namebuf[KSYM_NAME_LEN - 1] = 0; |
1da177e4 LT |
321 | namebuf[0] = 0; |
322 | ||
ffc50891 FBH |
323 | if (is_ksym_addr(addr)) { |
324 | unsigned long pos; | |
1da177e4 | 325 | |
ffc50891 | 326 | pos = get_symbol_pos(addr, symbolsize, offset); |
1da177e4 | 327 | /* Grab name */ |
e3f26752 CG |
328 | kallsyms_expand_symbol(get_symbol_offset(pos), |
329 | namebuf, KSYM_NAME_LEN); | |
7a74fc49 KM |
330 | if (modname) |
331 | *modname = NULL; | |
1da177e4 LT |
332 | return namebuf; |
333 | } | |
334 | ||
74451e66 DB |
335 | /* See if it's in a module or a BPF JITed image. */ |
336 | ret = module_address_lookup(addr, symbolsize, offset, | |
337 | modname, namebuf); | |
338 | if (!ret) | |
339 | ret = bpf_address_lookup(addr, symbolsize, | |
340 | offset, modname, namebuf); | |
aba4b5c2 SRV |
341 | |
342 | if (!ret) | |
343 | ret = ftrace_mod_address_lookup(addr, symbolsize, | |
344 | offset, modname, namebuf); | |
74451e66 | 345 | return ret; |
1da177e4 LT |
346 | } |
347 | ||
9d65cb4a AD |
348 | int lookup_symbol_name(unsigned long addr, char *symname) |
349 | { | |
350 | symname[0] = '\0'; | |
9281acea | 351 | symname[KSYM_NAME_LEN - 1] = '\0'; |
9d65cb4a AD |
352 | |
353 | if (is_ksym_addr(addr)) { | |
354 | unsigned long pos; | |
355 | ||
356 | pos = get_symbol_pos(addr, NULL, NULL); | |
357 | /* Grab name */ | |
e3f26752 CG |
358 | kallsyms_expand_symbol(get_symbol_offset(pos), |
359 | symname, KSYM_NAME_LEN); | |
9d65cb4a AD |
360 | return 0; |
361 | } | |
ad6ccfad | 362 | /* See if it's in a module. */ |
9d65cb4a AD |
363 | return lookup_module_symbol_name(addr, symname); |
364 | } | |
365 | ||
a5c43dae AD |
366 | int lookup_symbol_attrs(unsigned long addr, unsigned long *size, |
367 | unsigned long *offset, char *modname, char *name) | |
368 | { | |
369 | name[0] = '\0'; | |
9281acea | 370 | name[KSYM_NAME_LEN - 1] = '\0'; |
a5c43dae AD |
371 | |
372 | if (is_ksym_addr(addr)) { | |
373 | unsigned long pos; | |
374 | ||
375 | pos = get_symbol_pos(addr, size, offset); | |
376 | /* Grab name */ | |
e3f26752 CG |
377 | kallsyms_expand_symbol(get_symbol_offset(pos), |
378 | name, KSYM_NAME_LEN); | |
a5c43dae AD |
379 | modname[0] = '\0'; |
380 | return 0; | |
381 | } | |
ad6ccfad | 382 | /* See if it's in a module. */ |
a5c43dae AD |
383 | return lookup_module_symbol_attrs(addr, size, offset, modname, name); |
384 | } | |
385 | ||
42e38083 | 386 | /* Look up a kernel symbol and return it in a text buffer. */ |
0f77a8d3 | 387 | static int __sprint_symbol(char *buffer, unsigned long address, |
4796dd20 | 388 | int symbol_offset, int add_offset) |
1da177e4 LT |
389 | { |
390 | char *modname; | |
391 | const char *name; | |
392 | unsigned long offset, size; | |
966c8c12 | 393 | int len; |
1da177e4 | 394 | |
0f77a8d3 | 395 | address += symbol_offset; |
966c8c12 | 396 | name = kallsyms_lookup(address, &size, &offset, &modname, buffer); |
1da177e4 | 397 | if (!name) |
b86280aa | 398 | return sprintf(buffer, "0x%lx", address - symbol_offset); |
19769b76 | 399 | |
966c8c12 HD |
400 | if (name != buffer) |
401 | strcpy(buffer, name); | |
402 | len = strlen(buffer); | |
0f77a8d3 | 403 | offset -= symbol_offset; |
966c8c12 | 404 | |
4796dd20 SB |
405 | if (add_offset) |
406 | len += sprintf(buffer + len, "+%#lx/%#lx", offset, size); | |
407 | ||
19769b76 | 408 | if (modname) |
4796dd20 | 409 | len += sprintf(buffer + len, " [%s]", modname); |
966c8c12 HD |
410 | |
411 | return len; | |
42e38083 | 412 | } |
0f77a8d3 NK |
413 | |
414 | /** | |
415 | * sprint_symbol - Look up a kernel symbol and return it in a text buffer | |
416 | * @buffer: buffer to be stored | |
417 | * @address: address to lookup | |
418 | * | |
419 | * This function looks up a kernel symbol with @address and stores its name, | |
420 | * offset, size and module name to @buffer if possible. If no symbol was found, | |
421 | * just saves its @address as is. | |
422 | * | |
423 | * This function returns the number of bytes stored in @buffer. | |
424 | */ | |
425 | int sprint_symbol(char *buffer, unsigned long address) | |
426 | { | |
4796dd20 | 427 | return __sprint_symbol(buffer, address, 0, 1); |
0f77a8d3 | 428 | } |
ad6ccfad | 429 | EXPORT_SYMBOL_GPL(sprint_symbol); |
42e38083 | 430 | |
4796dd20 SB |
431 | /** |
432 | * sprint_symbol_no_offset - Look up a kernel symbol and return it in a text buffer | |
433 | * @buffer: buffer to be stored | |
434 | * @address: address to lookup | |
435 | * | |
436 | * This function looks up a kernel symbol with @address and stores its name | |
437 | * and module name to @buffer if possible. If no symbol was found, just saves | |
438 | * its @address as is. | |
439 | * | |
440 | * This function returns the number of bytes stored in @buffer. | |
441 | */ | |
442 | int sprint_symbol_no_offset(char *buffer, unsigned long address) | |
443 | { | |
444 | return __sprint_symbol(buffer, address, 0, 0); | |
445 | } | |
446 | EXPORT_SYMBOL_GPL(sprint_symbol_no_offset); | |
447 | ||
0f77a8d3 NK |
448 | /** |
449 | * sprint_backtrace - Look up a backtrace symbol and return it in a text buffer | |
450 | * @buffer: buffer to be stored | |
451 | * @address: address to lookup | |
452 | * | |
453 | * This function is for stack backtrace and does the same thing as | |
454 | * sprint_symbol() but with modified/decreased @address. If there is a | |
455 | * tail-call to the function marked "noreturn", gcc optimized out code after | |
456 | * the call so that the stack-saved return address could point outside of the | |
457 | * caller. This function ensures that kallsyms will find the original caller | |
458 | * by decreasing @address. | |
459 | * | |
460 | * This function returns the number of bytes stored in @buffer. | |
461 | */ | |
462 | int sprint_backtrace(char *buffer, unsigned long address) | |
463 | { | |
4796dd20 | 464 | return __sprint_symbol(buffer, address, -1, 1); |
0f77a8d3 NK |
465 | } |
466 | ||
42e38083 RP |
467 | /* Look up a kernel symbol and print it to the kernel messages. */ |
468 | void __print_symbol(const char *fmt, unsigned long address) | |
469 | { | |
470 | char buffer[KSYM_SYMBOL_LEN]; | |
471 | ||
472 | sprint_symbol(buffer, address); | |
473 | ||
1da177e4 LT |
474 | printk(fmt, buffer); |
475 | } | |
ad6ccfad | 476 | EXPORT_SYMBOL(__print_symbol); |
1da177e4 LT |
477 | |
478 | /* To avoid using get_symbol_offset for every symbol, we carry prefix along. */ | |
ad6ccfad | 479 | struct kallsym_iter { |
1da177e4 | 480 | loff_t pos; |
74451e66 | 481 | loff_t pos_mod_end; |
1da177e4 | 482 | unsigned long value; |
ad6ccfad | 483 | unsigned int nameoff; /* If iterating in core kernel symbols. */ |
1da177e4 | 484 | char type; |
9281acea TH |
485 | char name[KSYM_NAME_LEN]; |
486 | char module_name[MODULE_NAME_LEN]; | |
ea07890a | 487 | int exported; |
1da177e4 LT |
488 | }; |
489 | ||
1da177e4 LT |
490 | static int get_ksymbol_mod(struct kallsym_iter *iter) |
491 | { | |
74451e66 DB |
492 | int ret = module_get_kallsym(iter->pos - kallsyms_num_syms, |
493 | &iter->value, &iter->type, | |
494 | iter->name, iter->module_name, | |
495 | &iter->exported); | |
496 | if (ret < 0) { | |
497 | iter->pos_mod_end = iter->pos; | |
1da177e4 | 498 | return 0; |
74451e66 DB |
499 | } |
500 | ||
1da177e4 LT |
501 | return 1; |
502 | } | |
503 | ||
74451e66 DB |
504 | static int get_ksymbol_bpf(struct kallsym_iter *iter) |
505 | { | |
506 | iter->module_name[0] = '\0'; | |
507 | iter->exported = 0; | |
508 | return bpf_get_kallsym(iter->pos - iter->pos_mod_end, | |
509 | &iter->value, &iter->type, | |
510 | iter->name) < 0 ? 0 : 1; | |
511 | } | |
512 | ||
1da177e4 LT |
513 | /* Returns space to next name. */ |
514 | static unsigned long get_ksymbol_core(struct kallsym_iter *iter) | |
515 | { | |
516 | unsigned off = iter->nameoff; | |
517 | ||
ea07890a | 518 | iter->module_name[0] = '\0'; |
2213e9a6 | 519 | iter->value = kallsyms_sym_address(iter->pos); |
1da177e4 LT |
520 | |
521 | iter->type = kallsyms_get_symbol_type(off); | |
522 | ||
e3f26752 | 523 | off = kallsyms_expand_symbol(off, iter->name, ARRAY_SIZE(iter->name)); |
1da177e4 LT |
524 | |
525 | return off - iter->nameoff; | |
526 | } | |
527 | ||
528 | static void reset_iter(struct kallsym_iter *iter, loff_t new_pos) | |
529 | { | |
530 | iter->name[0] = '\0'; | |
531 | iter->nameoff = get_symbol_offset(new_pos); | |
532 | iter->pos = new_pos; | |
74451e66 DB |
533 | if (new_pos == 0) |
534 | iter->pos_mod_end = 0; | |
535 | } | |
536 | ||
537 | static int update_iter_mod(struct kallsym_iter *iter, loff_t pos) | |
538 | { | |
539 | iter->pos = pos; | |
540 | ||
541 | if (iter->pos_mod_end > 0 && | |
542 | iter->pos_mod_end < iter->pos) | |
543 | return get_ksymbol_bpf(iter); | |
544 | ||
545 | if (!get_ksymbol_mod(iter)) | |
546 | return get_ksymbol_bpf(iter); | |
547 | ||
548 | return 1; | |
1da177e4 LT |
549 | } |
550 | ||
551 | /* Returns false if pos at or past end of file. */ | |
552 | static int update_iter(struct kallsym_iter *iter, loff_t pos) | |
553 | { | |
554 | /* Module symbols can be accessed randomly. */ | |
74451e66 DB |
555 | if (pos >= kallsyms_num_syms) |
556 | return update_iter_mod(iter, pos); | |
ad6ccfad | 557 | |
1da177e4 LT |
558 | /* If we're not on the desired position, reset to new position. */ |
559 | if (pos != iter->pos) | |
560 | reset_iter(iter, pos); | |
561 | ||
562 | iter->nameoff += get_ksymbol_core(iter); | |
563 | iter->pos++; | |
564 | ||
565 | return 1; | |
566 | } | |
567 | ||
568 | static void *s_next(struct seq_file *m, void *p, loff_t *pos) | |
569 | { | |
570 | (*pos)++; | |
571 | ||
572 | if (!update_iter(m->private, *pos)) | |
573 | return NULL; | |
574 | return p; | |
575 | } | |
576 | ||
577 | static void *s_start(struct seq_file *m, loff_t *pos) | |
578 | { | |
579 | if (!update_iter(m->private, *pos)) | |
580 | return NULL; | |
581 | return m->private; | |
582 | } | |
583 | ||
584 | static void s_stop(struct seq_file *m, void *p) | |
585 | { | |
586 | } | |
587 | ||
588 | static int s_show(struct seq_file *m, void *p) | |
589 | { | |
590 | struct kallsym_iter *iter = m->private; | |
591 | ||
ad6ccfad | 592 | /* Some debugging symbols have no name. Ignore them. */ |
1da177e4 LT |
593 | if (!iter->name[0]) |
594 | return 0; | |
595 | ||
ea07890a AD |
596 | if (iter->module_name[0]) { |
597 | char type; | |
598 | ||
ad6ccfad MK |
599 | /* |
600 | * Label it "global" if it is exported, | |
601 | * "local" if not exported. | |
602 | */ | |
ea07890a AD |
603 | type = iter->exported ? toupper(iter->type) : |
604 | tolower(iter->type); | |
9f36e2c4 KC |
605 | seq_printf(m, "%pK %c %s\t[%s]\n", (void *)iter->value, |
606 | type, iter->name, iter->module_name); | |
ea07890a | 607 | } else |
9f36e2c4 KC |
608 | seq_printf(m, "%pK %c %s\n", (void *)iter->value, |
609 | iter->type, iter->name); | |
1da177e4 LT |
610 | return 0; |
611 | } | |
612 | ||
15ad7cdc | 613 | static const struct seq_operations kallsyms_op = { |
1da177e4 LT |
614 | .start = s_start, |
615 | .next = s_next, | |
616 | .stop = s_stop, | |
617 | .show = s_show | |
618 | }; | |
619 | ||
620 | static int kallsyms_open(struct inode *inode, struct file *file) | |
621 | { | |
ad6ccfad MK |
622 | /* |
623 | * We keep iterator in m->private, since normal case is to | |
1da177e4 | 624 | * s_start from where we left off, so we avoid doing |
ad6ccfad MK |
625 | * using get_symbol_offset for every symbol. |
626 | */ | |
1da177e4 | 627 | struct kallsym_iter *iter; |
0049f26a | 628 | iter = __seq_open_private(file, &kallsyms_op, sizeof(*iter)); |
1da177e4 LT |
629 | if (!iter) |
630 | return -ENOMEM; | |
631 | reset_iter(iter, 0); | |
632 | ||
0049f26a | 633 | return 0; |
1da177e4 LT |
634 | } |
635 | ||
67fc4e0c JW |
636 | #ifdef CONFIG_KGDB_KDB |
637 | const char *kdb_walk_kallsyms(loff_t *pos) | |
638 | { | |
639 | static struct kallsym_iter kdb_walk_kallsyms_iter; | |
640 | if (*pos == 0) { | |
641 | memset(&kdb_walk_kallsyms_iter, 0, | |
642 | sizeof(kdb_walk_kallsyms_iter)); | |
643 | reset_iter(&kdb_walk_kallsyms_iter, 0); | |
644 | } | |
645 | while (1) { | |
646 | if (!update_iter(&kdb_walk_kallsyms_iter, *pos)) | |
647 | return NULL; | |
648 | ++*pos; | |
649 | /* Some debugging symbols have no name. Ignore them. */ | |
650 | if (kdb_walk_kallsyms_iter.name[0]) | |
651 | return kdb_walk_kallsyms_iter.name; | |
652 | } | |
653 | } | |
654 | #endif /* CONFIG_KGDB_KDB */ | |
655 | ||
15ad7cdc | 656 | static const struct file_operations kallsyms_operations = { |
1da177e4 LT |
657 | .open = kallsyms_open, |
658 | .read = seq_read, | |
659 | .llseek = seq_lseek, | |
5a0c6a0d | 660 | .release = seq_release_private, |
1da177e4 LT |
661 | }; |
662 | ||
663 | static int __init kallsyms_init(void) | |
664 | { | |
33e0d57f | 665 | proc_create("kallsyms", 0444, NULL, &kallsyms_operations); |
1da177e4 LT |
666 | return 0; |
667 | } | |
ad6ccfad | 668 | device_initcall(kallsyms_init); |